Topological semimetals are a frontier of quantum materials. In multiband electronic systems, topological band crossings can form closed curves, known as nodal lines. In the presence of spin–orbit coupling and/or symmetry-breaking operations, topological nodal lines can break into Dirac/Weyl nodes and give rise to interesting transport properties, such as the chiral anomaly and giant anomalous Hall effect. Recently, the time-reversal symmetry-breaking induced Weyl fermions are observed in a kagome-metal Co₃Sn₂S₂, triggering interests in nodal-line excitations in multiband kagome systems. Here, using first-principles calculations and symmetry-based indicator theories, we find six endless nodal lines along the stacking direction of kagome layers and two nodal rings in the kagome plane in nonmagnetic Ni₃In₂S₂. The linear dipsersive electronic structure, confirmed by angle-resolved photoemission spectroscopy, induces large magnetoresistance up to 2000% at 9 T. Our results establish a diverse topological landscape of multiband kagome metals.

拓扑半金属是量子材料的前沿。在多频带电子系统中，拓扑带交叉可以形成闭合曲线，称为节点线。在存在自旋轨道耦合和/或对称破缺操作的情况下，拓扑节点线可以突破 Dirac/Weyl 节点并产生有趣的传输特性，例如手性异常和巨大异常霍尔效应。最近，在kagome-metal Co ₃ Sn ₂ S _{2中观察到时间反演对称破缺诱导的Weyl费米子}，引发对多频带kagome系统中节点线激励的兴趣。_{在这里，利用第一性原理计算和基于对称性的指标理论，我们在非磁性Ni 3} In ₂ S ₂中发现了沿kagome层堆叠方向的六个无限节线和kagome平面中的两个节环。由角分辨光电子能谱证实的线性色散电子结构在 9 T 时诱导高达 2000% 的大磁阻。我们的结果建立了多波段 kagome 金属的多样化拓扑景观。